Many industries have a need for functional polymers and articles made therefrom. By way of example, a food, medical, or pharmaceutical production line maintains tight audit control of service articles that enter the medical or manufacturing facility to assure such articles do not accidently enter the process or production stream as a contaminant that can be fragmented into dangerous shards. Historically, plastics have been precluded from some environments due to the inability to locate such articles with product screening metal or X-ray detectors. Recently, plastic articles have been developed that are filled with metal particulate or barium sulfate, as detailed US Patent Application Publication US20120241589 that are detectable with magnetic or X-ray detectors, yet still process as injection moldable thermoplastics and operate in manner similar to their unfilled conventional counterparts.
By way of example, U.S. Pat. No. 5,897,673 teaches fibers containing fine metallic particles that are cross-linked to the polymeric fiber. While various pure metals are contemplated in the literature, little attention has been paid to the unique problems associated with stainless steel particulate or other functional particulates. As many manufactured substances can only be exposed to stainless steel or other functional particulates, the lack of stainless steel or other functional particle filled fibers precludes the usage of many useful articles from these controlled manufacturing sites. By way of example various wipes, hair covers, suits, aprons and shoe covers and other manufacturing aids or personal protective equipment if made from stainless steel or other functional particulates containing fibers could allow better quality control of manufacturing with less stringent audit processes, as any such articles lost in a production stream could be detected by X-ray or magnetic anomaly. However, injection molded parts containing loading of metals or electron dense substances needed for detection are limiting in terms of the materials that can be formed.
Thus, there exists a need for a spun thermoplastic fiber filled with particulate, the particulate rendering a resultant non-woven article either detectable in a production context alone or also to include additional functional particulate. There also exists a need for such fibers that process and retain properties of conventional thermoplastic fibers to promote production of various articles from fibers that have the added benefit of imparting functional properties while operating in a manner similar to conventional articles.